@ma740988 - I had the ISO PSA test done after my PSA went to 4.2. That med to an MRI, which led to the biopsy. My doctor was very thorough and didn't skip a step. Biopsy led to a 3+4, grade 2, 2 small lesions which were 7mm and 8mm. PET scan was negative except the prostate. Culminated in 5 Radixact treatments over a 2-week period. That ended 3 weeks ago so dealing with some annoyances. Bottom line of all this...don't let them skip steps and guess. If a doctor is including the ISO, then you probably have a good one.